Fuel flow regulator for supercharged aircraft engines



April 22, 1952 D. SCHMlTT 2,593,302

FUEL FLOW REGULATOR FOR SUPERCHARGED AIRCRAFT ENGINES Filed April 19,1948 5 Sheets-Sheet l Z8 (CONNECTED TO THE MANIFOLD) April 22, 1952 D.SCHMITT 2,593,802

FUEL FLOW REGULATOR FOR SUPERCHARGED AIRCRAFT mamas Filed April 19, 19485 Sheets-Sheet 2 VVA y ATTORNEYS April 22, 1952 v D. SCHMITT 2,593,802

FUEL FLOW REGULATOR FOR SUPERCHARGED AIRCRAFT ENGINES Filed April 19.1948 5- Sheets-Shut s INVENTOR o @il'St/Zillilt 8. 5-. WWW,

ATTORNEYJ A ril 22, 1952 D. SCHMITT 2,593,802

FUEL FLOW REGULATOR FOR SUPERCHARGED AIRCRAFT ENGINES Filed Agril 19,1948 5 Sheets-Sheet 4 jfesire Scllmili BY 6 5 Wham/c4 ATTORNEYS April22, 1952 D. SCHMITT ,8

FUEL FLOW REGULATOR FOR SUPERCHARGED AIRCRAFT ENGINES Filed April 19,1948 5 s h'ets sheet 5 INVENIOR .Dwuv

ATTORNEY5 Fatenteci Apr. 22, 1952 FUEL FLOW REGULATOR FOR SUPER- CHARGEDAIRCRAFT ENGINES Dsir Schmitt, Saint-Maur, France, assignor to Ateliersde Constructions Lavalette, Saint- Ouen, France, a French corporationApplication April 19, 1948, Serial No. 21,947

In France April 18, 1947 7 Claims. (c1. 122-103) Granted An aircraftengine operates under well defined conditions such as speed, inductionpressure, induction .itemperature, altitude, richness of the mixture ofthe charge and an air-flow coefficient for the cylinders and thefunction of a regulator is to secure automatically and for each speed ofthe engine a suitable ratio of the fuel and air supplied to the engine.d

The weight of the fuel to be supplied to a cylinder per cycle depends ontwo essential and in dependent factors: Y

a. On .the weight of air introduced per cycle into the cylinder, and

b. On the richness of the mixture.

The weight of air introduced per cycle into a two or four strokecylinder is itself a function of several variables which are the intakepressure, the intake temperature, the exhaust pressure, i. e. thealtitude and the fiowcoefilcient, the latter in turn being a function ofthe engine speed in revolutions per minute, of the richness of themixture and of all the previously mentioned variables.

The richness of the mixture however is a function only, of the operatingrate of the engine, i. e. of its speed in revolutions per minute and ofthe adjustment of the intake pres-sure. It therefore depends upon theposition of the throttle. This pressure is not always equal necessarilyto that corresponding to the position of the throttle. As long as theengine operates at an altitude lower than or equal to the criticalaltitude, the intake pressure corresponds to the position of thethrottle.

Above the critical altitude the richness of the mixture is a function ofthe position of the under the provisions of sec. 14, act of March 2,1927; 357 0. G. 5)

controlling the product of the last two mentioned.

variables, namely: Thefiow coefficient by the richness of the mixture.

A further object of the invention is to provide means whereby the aboveelements act through a suitable mechanism on the means for supplyingfuel to the engine whereby an exact mixture of the fuel is provided. Fora proper understanding of the invention the 'adjustmentjof the flow offuel will be studied successively as a function of the five variablesabove mentioned. In the following description it has been assumed thatthe regulator controls a pump for supplying the fuel although theinvention is not limited to such an application. o

With the above and other objects in view which will become apparent fromthe description below, the invention is shown'in the drawings in whichFig. 1 is a diagrammatic view of the regulator;

Fig. 2 is a diagrammatic view illustrating the correction of theregulator in'accordance with the temperature;

Fig. 3 is a diagram of the fuel supplied by the pump as a function ofthe positions taken by the regulator;

Fig. 4 is a diagrammatic VlEW' modified construction;

' Fig. 5 is 'a similar view indicating another modified construction; I

Fig; 6 is a similar view indicating a still further modification;

Fig. 7 is a similar view of a illustrating a fourth modification, and

throttle and the intake pressure decreases while the richness of themixture remains constant. 'I

Theweight of the fuel introduced per cycle into a cylinder will thus bea function at the same time of the following variables:

1. The intake pressure.

2. The intake temperature.

3. The altitude.

l The flow coefficient.

5. The richness.

An object of the present invention is to provide a fuel fiow regulatorfor super-charged internal combustion engines equipped with means forsupplying the fuel.

It is an object of the invention to provide'a a cam connected to thethrottle having a profile regulator comprising on onehand special de-Fig. 8 is a similar view illustrating a fifth modification. 4 Y

The regulation of the fuel flow as a function of the intake pressurewill first be considered. Referring to Fig.- 1 a chamber 24 is incommunication with the intake manifold, not shown, by means of a pipe28. In chamber 24 an an'eroid capsule 25 is positioned having one of itsends attached to a wall of the chamber and its other end connected to arod 2 1 which in turnis pivotally connected to a lever 20. The lever '20in tum acts at its lower end on a rod 58 which drives'by means of a fork6| a pin 60 having a base slidably mounted in an enlarged openingprovided in the lever 62. w

Thelever -62 is pivotally mounted upon shaft '65 and 'coactswith theslide valve 51 of a servo motor. The slidevalve reciprocates within apiston 54 and the piston 54 reciprocates within the cylinder 5|. Oilunder pressure enters through a duct 52 anda shoulder 56'on the slidevalve 51 controls a duct 53 leading to the; space 3 49. A third duct 55permits the return of oil from thespace 49 to the casing of theregulator.

The piston 54 has attached thereto a rod 48 terminating in a shoulderwhich bears against a wall of a chamber provided in a member 29. Aspring 41 constantly urges the member 29 against the shoulder upon therod 48 so that the member 29 follows the movements of the piston 54.Attached to the member 29 is a rod 3| terminating in a yoke which driveseither directly or through a system of levers, pivots or connectingrods, the control lever or rod of the fuel supply pump.

When the intake pressure increases from Pa to P1 the capsule 25 iscompressed. This causes the rod 2! to move the lever 20 from left toright as seen in Fig. 1. With the pin 19 remaining fixed temporarily thelower fork of the lever 29 will move the rod 58 from left to right andby fork BI and pin 69 the lever 52 is swun counterclockwise about theshaft 65 which is temporarily fixed. The slide valve 51 therefore ismoved towards the right" and the shoulder 56 uncovers the duct 53thereby placing the space 49 in communication with theoil evacuationduct 55 bringing. about a pressure drop inside the space 49. Due to theaction of the spring 41 the member 29 and piston 54 are also movedtowards the right. 7

With a portion of the oil' contained in the space 49 expelled throughthe duct 53 and the evacuation duct 55 the motion continues until thepiston 54 has caught up With-the movement of the slide 51. At such timethe duct 53 is again blocked by the shoulder 56 on the slide valve. Thismotion from left to right causes the rod 3| to bring about a larger flowof fuel to the engine In case there is a decrease in the intake pressurethen the capsule 25 expands and the motions described above take placein the opposite direction.-

The shoulder 56 on the slide valve 51 in moving-towards the left in suchcase uncovers the opening of duct 53 and thus places duct 52 incommunication with space 49; In such case oil under pressure enteringthrough the. duct 52 will bring about a displacement of the pistontowards the left. The spring 4'! is compressed and aspreviouslydescribed all motion will stop as soon as the lower opening ofthe duct53.is again blocked by'the shoulder 56 of the slide valve 51.

A movement towards the left brings about a decrease in the flow of fuelfrom the. supply pump.

The movements of the slide valve 51 therefore directly controls the fuelsupply from the pump to the engine.

The means for securing an adjustment of the fuel flow as a function ofthe intake temperature will now be described.

The means for bringing this about comprises athermostat 59 connected bya tube 69 to the space 19. The space 10, the tube 69, and the thermostatform a closed space which is filled with a non-congealable liquid=havinga high coeiiicient of expansion; The thermostat 59 is located in'th'eintake manifold. In order to prevent any vaporization of the liquid atthehigh temperatures prevailing in the intake manifold a; spring 12-acts upon a capsule H which are housed in the space 19.

The-capsule H has fixed thereto a rod 13 which coacts with a forked bellcrank lever 2 pivoted at I. The lever 2 in turn coacts with a rod 64 4provided with a fork 63 which encloses the pin 60. By this means thebase of the pin-66 may be displaced by the movements of the rod 64within the enlarged opening of the lever 62 independently of theposition of the rod 58.

To secure a temperature correction of the fuel supply the operation isas follows:

Let us assume that the engine is working at a certain intake temperatureTo and that the lever 62 has the position :c:cn indicated on Fig. 2, itsvertical position (Fig. 1) corresponding to a zero flow.

Let us assume now that the intake temperature drops from To to T1, withall the other variables, i. e. the intake pressure, the intaketemperature, the altitude, the flow coefficient, the mixture richnessremaining constant, including the speed of the engine.

The liquid contained in the thermostat 59 will decrease in-volume, whichwill cause the capsule H to lengthen as part of the liquid containedinside'thespace 19 will flow through the capillary tube 69 intothermostat 59. Through rod 13, and lever 2, the capsule causes the rod94 to move upwardly.

The pin 69, Fig. 2, is guided vertically byv fork 6|, the latterremaining motionless for the time being. Fork 63 drives it from pint Oto point I. Due tothis fact, the lever 62 is inclined more and passesfrom position x.ro to position .'1,-.'L1. Consequently the slide valve5'!" is pushed by the amount arc-m1 from left to right, which has theeifect of increasing the flow of fuel.

It can easily be shown that the displacements of the rod 64 are ininverse proportion to those of the slide valve 51, which means that theflow of gasolineis in inverse proportion to the intake temperature. Themechanism therefore ensures a correct variation of the flow of fuel as afunction of the intake temperature.

It is to be noted that for the vertical position of the lever 62, i. e.at its position of zero flow, the temperature variations have no actionon this lever, while itsaction becomes more and more important as theair and fuel flow and, consequently the power of the motor increases.

The adjustment of the fuel flow as a function of the exhaust pressuredrop or altitude correction will now be described.

The means forthis adjustment comprises an aneroid capsule 23. Thiscapsule is housed inside a chamber 22 which communicates with theoutside atmosphere or with the exhaust manifold. The capsule 23 isattached at one of its ends to a wall of chamber 22' and acts at itsfreeend'ona rod 2l' which moves the lever 29 by means of pin i9 and anupper fork on lever 29.

When the atmospheric pressure, which may be assumed to be substantiallyidentical with the exhaust pressure decreases, i. e. at higher altitude,the capsule 23 expands. It imparts to rod 2| a right to left motion, theupper fork of lever 20 follows this motion while the lower fork of thesame lever is displaced from left to right, the. axle 26 remainingmotionless. Due to this fact, the rod 58 is also driven in the samedirection and acts on the slide valve 5! through the fork 6|, pin 69 andthe lever 62. The slide valve 51 moves from left to right, causing anincrease in-the fuel supply. In case of a decrease in altitude, all themotions take place in the opposite direction. The-result will be adecrease in the flowof the fuel.

The adjustment of the mixture richness is brought about as follows.

be effected as a function of the speed of the engine or independentlythereof and the means provided comprises a cam I having an arm IIpivotally connected to a connecting rod I2 which, in turn, isarticulated at its lower part with a bell crank lever II. The latter,through rod I8 is connected with the throttle controlling the speeds ofthe engine, together with its intake pressure.

The pin 6 of a lever 3 bears on cam 'I. The shaft I, about which rotatesthe lever 2 transmitting the temperature variations is associated withthe lower branch of lever 3. Pin 6 is constantly urged against the camby means of a spring blade 63. The lever 3 oscillates on a fixed shaft4. I

Let us assume the passage from an operating condition of a richness R0to another one of a richness R1 lower than R0. Due to the movement ofthe throttle causing this change in operating conditions, the rod I8moves from right to left. The effect of this motion is to rotate the caml in a counterclockwise direction. The pin 6 of lever 3 falls into therecess of the cam and the lever 3 rotates in a clockwise direction. The

. shaft I, following this motion causes a lifting of the upper fork oflever 2 and a lowering of the other fork of said lever. The rod 64,therefore, moves downwardly, causing a decrease in' the fuel supplycorresponding to the new richness.

The essential result of this operation is the change in themultiplication ratio of lever 2, which ratio is increased by theoperation considered.

For an unchanged intake temperature, the fork B3 is thus at a lowerposition, i. e. the fuel flow is weaker and the richness of the mixturewill be decreased, (see Fig. 2).

The adjustment of the richness independently of the operating conditionsof the engine takes place as follows.

The cam 'I is mounted on an eccentric 9 keyed on a shaft 8. The rotationof this shaft is controlled by a lever I3 articulated-with a connectingrod I5 which is operated by the pilot.

To increase the richness independently of the operating conditions ofthe engine, the connecting rod I5 is moved from left to right. Lever I3moves the eccentric 9 in a counterclockwise direction moving the cam Ito the left, and, consequently, the rotation of the lever 3 in acounterclockwise direction. The shaft I rotates about the shaft 4,driving the lever 2. For an unchanged intake temperature the pin of rod-I3 remains motionless while the lower fork of lever 2 raises the rod 64,thus causing, according to Fig. 2, an increase of the fuel fiow, i. e.of the richness.

It must be understood in all the above description, that the expressionrichness implies the product richness times the fiow factor.

The correction for the operation of the regulator at different speeds ofthe supply pump will now be described. The regulator contains a specialmechanis for the "purpose of standardizin the displacements of theregulating element for each speed of the pump to ensure normal operationof the other correction mechanisms.

A basic condition being given, defining the zero condition for aposition 0 of the regulating element, the correcting mechanism causes,for any other pump condition an artificial shifting of the zerocondition defining always the. zero condition by anextrapolation.

The main element of this correcting mechanism is cam I0 which can rotatefreely about shaft 8. This cam is connected with the throttle throughthe arm I4, the connecting rod I6, the lever I1 and the rod I8. Thissame lever I! thus controls both cams I and I0.

One cam Ill bears the upper arm of lever 66.

This lever rotates about a fixed axis..5 and carries.

at its lower end shaft 35 on whichrotates the lever 62. Lever 66 isconstantly urged agains the cam III by a spring 61. V 1

Let us assume that at m revolutions per minu the fuel supply pumpoperates on a given engine in accordance with curve I (Fig. 3) (forinstance in the economical cruising condition) and that at speed m itworks according to curve 2 whose extension does not go through the zeroposition of the adjustment element for the output. Let A be a point ofoutput, curve 2, corresponding to the correct output of the pump for agiven working condition of the engine (for instance for the rated climboutput) and let T be the intake temperature at which this engine works.

Let us suppose first that the shaft 65 of lever 62 (Fig. 1) is immovableand that, to the verticalv position of this lever corresponds the zeroposi-. tion of the pump regulating element In such a case, if thetemperature varies from T to T T, it will not be the initial output Q8.of the. pump which will be multiplied by the ratio -T/T, but only therun of the regulating element La. The new run will be G II%7 but the newoutput will only be Q3" instead of Q2. the latter being the new correctoutput.

For the new output to be Qt, the distance Ya, instead of La must bemultiplied by the ratio T/ T. Due to this multiplication, Ya will.become Ya and Q9. will become Qa', i. e. the output correction will beaccurate.

For this to be possible, the vertical position of lever 62 will have tocorrespond, for the condition considered, not to the position 0 of theregulating element of the pump, but to a position 0' corresponding tothe point of intersection of curve 2 of the outputs with theaxis of theabscissae. Thus, to obtain exact corrections for the fuel outputs, shaft65 must be capable ofsliding horizontally in such a way that the originof the output'curves (Fig. 3) be artificially modified.

The above regulation arrangement comprises, further, a rod 32 allowingthe cutting off of the fuel fiow by pushing from right to left. Thisoperation is effected by the pilot, the rod 32 being connected to meansunder his control. The plate 30, on the rod 32 can press against themember 29 and disengage it from rod 48 by compressing the spring 41. Rod3|, following this motion from right to left, cuts off the flow from thepump whatever may be the momentary position of piston 54. I i i In caseof a failure of the regulation mechanism, an emergency control isprovided allowing th pilot to regulate the fuel flow himself during atime interval as short as possible.

The member 23 has, at its lower part, a rack 33 which meshes with a gearsector of a drum 34. In normal operation, this drum rotates freely aboutthe shaft 38. This shaft is associated with a lever 39 which can beoperated by the pilot. The shaft 38 has a housing wherein cansllde astop element 4| which is applied against a fixed cylindrical surface3I,by means of. a spring, 35.

The drum 34 is. provided. with. a hole 36. The lower arm of a bell cranklever 44 presses on the cam 43, associated with the shaft 38 while thevertical arm drives the slide valve 48. The bell crank lever 44 isapplied against a cam 43 by a spring.

Let us assume the regulation mechanism locked, following an accident.From that time on, the pump gives a constant output. The pilot thenoperates the lever 39 by moving it from right to left. The cam 43rotates counterclockwise. The pin 42 of lever 44 moves closer to thecenter of the cam while the fork 45 of the same lever drives the slide46 towards the left. Due to this action, the orifice 50 of space 49 isuncovered and the oil enclosed in said space flows to the outside. Thepiston 54 can thus be displaced freely, the entrance duct 52 for theoil, being closed by the shoulder of the same slide 46.

Due to the rotation of shaft 353, the stop element 4! jumps from thecylindrical surface 31 into the hole 36 of the drum, which is thusdriven directly by this lever. The gear sector of the drum, in turn,drives the rack bar of the member 29 and, consequently, the regulatingelement for the pump.

The above description of the operation of the regulator is not limitedas regards the arrangement of the various elements. It is possible toprovide other arrangements, for the altitude and intake pressurecapsules and by way of example, five different modifications are givenhereunder.

A first modification is shown in Fig. 4.

The regulation device of Fig. 4 comprises an aneroid capsule 25 enclosedin a chamber 24 communicating with the inlet manifold.

With respect to this aneroid capsule '25 there is associated therewith asecond aneroid capsule 23 subject to atmospheric pressure. The twocapsules are connected by a lever 58 comprising the fork iii andcooperating with the pin 60 of the lever 62 controlling the regulationas has been indicated above.

Moreover, the lever 64 sliding as a function of the temperature and ofthe richness of the mixture has at its end the fork 63 also cooperatingwith the pin 65 of the lever 62 acting upon the regulation.

The arrangement shown in Fig. 4 operates in the following manner:

The intake pressure acts on the aneroid capsule 25 enclosed insidechamber 24 which communicates with the intake manifold. Th atmosphericpressure acts on the other aneroid capsule 23. The two capsules are inline. Their outer ends are fixed. Their inner ends are connected by afork carrying bar 58 which acts on the pin of .the slide block of lever62. The remaining mechanism is identical with that of Fig. 1,particularly as regards the temperature correction transmitted by thefork-carrying bar 64. It is seen from Fig. 4, that an increase of theintake pressure pa causes an increase of the output of the pump. Thesame thing takesplace upon a decrease of the atmospheric pressure 122,i. e. for an increase in altitude. A second modification is shown inFig. 5.

The arrangement of Fig. comprises an aneroid capsule 25 enclosed in achamber 24 communieating with the inlet manifold. At the interior ofthis capsule there is located a second aneroid capsule 23. communicatingwith atmospheric pressure. These two. capsules act upon a'lever 58-comprising a fork ii-acting upon the pin 60 of? the regulation controllever 62. In the same manner the lever 64 whose movement is a functionof the temperature and of the richness of the mixture has at its end afork 63 also cooperating with the pin 60 of the regulation control lever62.

The arrangement operates in the following manner:

The chamber 24 is in communication with the intake manifold. In thischamber is a double capsule. outwardly, it is acted upon by the intakepressure, inwardly by the atmospheric pressure. A vacuum exists betweenthe outer and inner envelopes and 23 respectively. The combined capsuleacts on a fork carrying rod 58 whose fork acts on the pin of the slideblock of lever 62. The remaining mechanism is identical with that ofFig. 1 particularly as regards the temperature correction transmittedonto lever 62 by the fork carrying rod 64.

It is seen from Fig. 5 that anincrease of the intake pressure pa willcause an increase of theoutput of the pump. The same thing will takefork 15 through the intermediary of a rod 21.

The lower fork of the double fork i5 acts upon the other slide block ofthe lever 62 of the regulation control while the upper fork acts uponthe slide block of a; lever 14. The lever 62 andthe lever 1'4 can turnindependently of one another about the point 65. Upon the other slideblock of the lever 62 a rod 64 acts in the same manner as above whosesliding is a function of the inlet-temperature and the mixture richness.The arrangementoperates in the following manner:

Three capsules are used in this system. The

difference in this system, with respect to the others, consists in thealtimetric capsule which is not a vacuum but rather a differentialcapsule, i. e. the intake pressure acts on the outside of the capsuleand the atmospheric or exhaust pressure acts on the inside. The correctadjustment of the gasoline flow is obtained by the deformation of aparallelogram, aswill be explained below.

The chamber 24 as well as the chamber 22 are in communication with theintake manifold. In these two chambers, there is thus constantly anintake. pressure ps. The chamber 24 contains the aneroid capsule 25, oneend of which is attached to the wall of the chamber and th travel of theother end of which is proportional to the atmospheric pressure. Thiscapsule acts on a double fork 75 through a rod 21, the lower fork actson the slide pin of lever 62 and the upper fork acts on the slide pin oflever 14. These two levers can turn independently about shaft 65. Theslide pin of lever 62 is acted upon also by the fork of rod 64 whichmoves perpendicularly to the rod 2'! and whose motions are proportionalto the intake temperaturaas explained above. The chamber 22 contains adifferential capsule 23 whereon the intake pressure pa acts outwardlyand the. exhaust (or atmospheric) pressure in actsinwardly. Thiscapsuleacts on the slidepin of lever H by means of 'thefork carrying rod2-! which is perpendicular to rod 21 andparallel to rod 64. Thedisplacements of rod 2| are thus proportional to pa-pz- At'its lowerend, lever a manner that the assembly of levers 62, 14, i6,

1'! forms a parallelogram, an apex of which is fixed, at 65. The leveri1 acts, by means of a fork, on the slide of the servo-motor 51 and,therefore, on the regulating element of the pump asexplainedabove.

Let us assume that the engine operates at well defined speed, intakepressure and intake temperature, and that only the exhaust pressurevaries.

Due to the drop in pressure a the capsule23 5 is shortened and lifts theslide pm of lever 14. Due to this motion, lever 11 passes from positiona: :z: to position xa:. It is found'that, by this motion, the slide 51is displaced from left to right bythe amount AY, i. e. the fuel flow isincreased proportionally to the difierence ia-p2.

A fourth modification is shown in Fig. 7. The arrangement of Fig. 7comprises in the same manner as set forth above an aneroid capsuleenclosed in a chamber 24 in communica- 25 tion with the inlet manifold.

The exhaust pressure acts upon another aneroid capsule 23. Theaneroidiccapsule 23 actsat upper portion of a lever 20 rotating about anaxis 18 while the other aneroid capsule 25 acts upon v the lever 20located at the other side of the oscillation axis of said lever. Thislever 20 terminates in a fork acting upon a pin integral with the end ofthe lever 58. The lever 58 terminates in a fork 6| cooperating as setforth above with as a function of the inlet temperature and the i0mixture richness. 4

The arrangement operates in the following manner:

The intake pressure pa acts on an aneroid capsule 25 enclosed inside atight chamber 24 which is in communication with the intake manifold andwherein, therefore, the intake pressure always obtains. Theexhaust oratmospheric pressure acts on another aneroid capsule 23. The

two capsules act on a common lever 20 which is articulated at a fixedpoint It. This lever, has

at its lower part a fork, which acts. in turn on the fork carrying rod58. The fork of this rod drives the slide pin 68 of the lever 62.

The remainder of the regulating mechanismr is identical with that ofFig. 1, particularly as regards the temperature correction transmittedby the fork carrying rod 64.

When the intake pressure increases capsule 25 is shortened and drivesrod 58 from left to,

right, the effect of which is an increase of the' fuel flow. The samemotion of rod 58 occurs when the exhaust pressure pz decreases, i. e.when the aircraftclimbs, and due tothis pressure .de-

crease,capsule 23 expands, causing the counter-. 5

clockwise rotation of lever 20.

A fifth modification is shown in Fig. 8.

The arrangement of Fig. 8 comprises an aneroid capsule 25 located inachamber 24 in communication with the inlet manifold and a second 70aneroid capsule 23 is subjected to the exhaust pressure. p Y

These two capsules act upon the respective ends of a lever 20oscillating about the axis I8.

This action is transmitted for each of the QZIP7'75 sules 23 and 25 by apin sliding in a fork'located at the end of lever 20. Moreover, themovement of the lever 20 under the action of the capsule 25 istransmitted to the capsule 23 subjected to the exhaust pressure. Thiscapsule 23 is connected at its other end to a rod 19 comprising a fork6| cooperating with the pin 60 of the regulation control lever 62. I, Inthe same manner as in the precedingmodification a rod 6 sliding as afunction of' the'temperature and the richness of'the mixture acts by afork 63 upon the pin 60 of the regulation control lever 62. v The deviceoperates as follows: f In this. variant, the intake and exhaust pressurecapsules are arranged in series. Theintake pressure. pa acts on capsule25." The free end of the capsule acts through a rodj'on the forked lever20 rotating about a fixed point 18.. The upper fork of this lever drivesa'second capsule 23 having rods at both ends sliding inside softfriction sockets. The exhaust'or atmospheric pressure acts on thiscapsule. ,The right hand rod 79, on this capsule, carries a fork which,in its motions, drives the slide pin of lever .62 and consequently theslide of the servo-motor controlling the flow.

Theremaining mechanism is identical withthat described above,particularly as regardsthe ternperature correctionwhich is transmittedby the fork carrying rod 64 ashas been explained above.

The operation is as follows;

When the intake pressure increases, capsule 25 contracts and lever 20rotates in a, clockwise direction. Capsule 23, with the fork carryingrod 19 moves to the right and increases the fuel flow. .L 1

When, under a constant intake pressure, the engine goes to a higheraltitude, capsule. '23 gradually expandsv and, in turn, increases thefuel flow by causing a left to right displacement of the slide of theservo-motor;

Iclaim: I ..1

1. In a fuel flow regulator for supercharged aircraft engines, a fuelsupply, a first forkcarrying rod, a second fork carrying rod, means formoving the first rod as a function .of, the. intake and barometricpressures, means for movingthe second rod as a function of'thein'taketemperature and of the adjustment of the richness of the fuel mixture,means for moving said rods perpendicularly to one another, a .lever arm,means for causing the simultaneous movements of said two rods to act on'said lever arm, an auxiliary armcontrolled by said leuerarm, means forcontrolling a fuel supply by the displacement of said auxiliary arm sothat said first .rodcauses motions of said controlling meansproportional to its own motions, in case said second rod remainsmotionless and that, similarly, said second rod motions of saidcontrolling means in inverse proportion to its own motions when saidfirst rod remains motionless. whereby the sim ltaneous movement of saidtwo rods ensures a fuel supply to the aircraft engine as a function ofthe barometric and intake, pressures, and of the intake temperature.

2. In a fuel flow regulator for supercharged aircraft engines, a fuelsupply, a first fork-carrying rod, a second fork-carrying rod, ananeroid capsule whose deformations are proportional to the intakepressure, means for coupling said capsule to said first fork carryingrod so that a deformation of said capsule causes a proportionalmovementof said rod, means for also causing said first .rod to slide asa function of the baror '11 metric, pressure, means for causing thesecond rod tov slide as a function of the intake pressure and of theadjustment of the richness of the fuel mixture, said rods being mountedperpendicularly to one another, a lever arm, means for causing the.simultaneous displacement of the two rods to act on said lever arm, anauxiliary arm cooperating; with, said lever arm, means for controllingsaid, .fuel supply by said auxiliary arm,

so that said first rod causes motions proportional to. its. own in saidcontrolling means, in case the second rod remains motionless and,similarly, said second rod causes, motions in inverse proportion to itsown in, said controlling means when the. first rod remains motionless,the. simultaneous displacement of the two rods thus ensuring .the supplyof fuel to the aircraft engine as a function of the intake pressure, ofthe barometric pressure, of the intake temperature and of the richnessof the fuel mixture.

3. In, a fuel flow regulator for supercharged aircraft engines, a fuelsupply, a first fork carrying rod, a second fork-carrying rod, ananeroid capsule whose deformations are proportional to the intakepressure, means for coupling said capsule to said first fork-carrying,rod so that a deformation of said capsule causes a proportional slidingor said rod, a second aneroid capsule whose deformations areproportional to the atmospheric pressure and therefore substantiallyproportional to the exhaust pressure, means for coupling said secondcapsule with said first fork-carrying rod so that a lengthening of saidcapsule causes a proportional sliding of said rod, means for causing thesecond rod to slide as a function of the intake temperature and of theadjustment of the richness of the fuel mixture, said rods being mountedto slide perpendicularly to one another, a lever arm, means for causingthe simultaneous displacement of said two rods to act on said lever arm,an auxiliary arm connected with said lever arm, means for controllingsaid fuel supply by the displacement of said auxiliary arm so that saidfirst rod causes motions proportional to its own in said controllingmeans, in case said second rod remains motionless and, similarly, saidsecond rod causes motions in inverse proportion to its own in saidcontrolling means, when the first rod remains motionless, thesimultaneous displacement of the two rods thus ensuring the fuel supplyfor the aircraft engine as a function of the intake pressure, of thebarometric pressure and of the intake temperature.

4. In a fuel flow regulator for supercharged aircraft engines, a fuelsupply, a first fork-carrying rod, a second fork-carrying rod, means forcausing said first rod to slide as a function of the intake andbarometric pressures, a thermostat located in the intake manifold, anairtight chamber, a conduit connecting said thermostat and chambers, acapsule in said chamber filled with a liquid having a high coefficientof expansion so that variations in said capsule are proportional to theintake temperature, means for coupling said capsule with said secondfork-carrying rod so that the sliding motions of said second rod areproportional to the intake temperature, means for also causing saidsecond rod to slide as a function of the richness of the fuel mixture,said rods being mounted to slide perpendicularly to one another, a leverarm, means for transmitting the simultaneous displacement of said tworods to said lever arm, an auxiliary arm connected to I said lever arm,means for controlling said fuel supply by the displacement of saidauxiliary arm so that said first rodcauses motions proportional to itsown in said controlling means in case said second rod remains motionlessand, similarly, said second rod causes motions in inverse proportion toits own in said controlling means, when the first rod remainsmotionless, the simultaneous displacement of the two rods thus ensuringthe supply of the aircraft engine with fuel as a function of the intakepressure of the barometric pressure, of the intake temperature and ofthe richness of the fuel mixture.

5. In a fuel flow regulator for supercharged aircraft engines afuelsupply, a first fork-carrying rod, a second fork-carrying rod, means forcausing said first rod to slide as a function of theintake andbarometric pressures, a thermostat located in the intake manifold of theengine, an airtight chamber, a conduit connecting said chamber andthermostat, a capsule filled with a liquid having a high coefiicient ofexpansion in said chamber so that deformations of said capsule areproportional to the intake temperature, a pivoted lever for transmittingthe motions of said capsule to said second fork-carrying rod, so thatthe slidings of said second rod are proportional to the intaketemperature, a shaft on which said lever pivots, a cam controlling theposition of said shaft, means for controlling said cam as a function ofthe position of the throttle which is itself a function of the richnessof the fuel mixture and of the fiow coefficient to vary the proportionratio of said lever and, consequently the amplitudes of the slidings ofsaid second rod as a function of the richness of the fuel mixture, saidrods being mounted to slide perpendicularly to one another, a lever arm,means for causing the simultaneous displacement of said two rods to acton said lever arm, an auxiliary arm connected to said lever arm, meansfor controllingsaid fuel supply by the displacement of said auxiliaryarm so that said first rod causes motions proportional to its own insaid controlling means in case said second rod remains motionless and,similarly, said second rod causes motions in inverse proportion to itsown in said controlling means when the first rod remains motionless, thesimultaneous dis placement of the two rods thus ensuring the fuel.supply for the aircraft engine as a function of the intake pressure, ofthe barometric pressure, of the intake temperature and of the richnessof the fuel mixture.

6. In a fuel flow regulator for .supercharged aircraft engines, a fuelsupply, a first fork-carrying rod, 2. second fork-carrying rod, meansfor causing said first rod to slide as a function of the intake andbarometric pressures, a thermostat located in the intake manifold of theengine, an airtight chamber, a conduit connecting said thermostat andchamber, a capsule filled with a liquid having a high coefficient ofexpansion so that deformation of said capsule is proportional to theintake temperature, a lever for transmitting the motions of said capsuleto said second fork-carrying rod, so that the movement of said secondrod is proportional to the intake temperature, a shaft on which saidlever is pivoted, a cam controlling the position of said shaft, meansfor controlling the position of said cam as a function of the positionofthe throttle which is itself a function of the richness of the fuelmixture and of the flow coeificient to vary the proportion ratio of saidlever and, consequently, the amplitude of the movements of said secondrod as a function of the richness of 13 the fuel mixture, an eccentricmanually operable on which said cam is mounted whereby a shiftin of saidcam by said eccentric causes a. variation in the adjustment for therichness of the mixture, said rods being mounted to slideperpendicularly to one another, a lever arm, means for causing thesimultaneous displacement of said two rods to act on said lever arm, anauxiliary arm connected to said lever arm, means for controlling saidfuel supply by the displacement of said auxiliary arm so that said firstrod causes motions proportional to its own in said controlling means incase the second rod remains motionless, and, similarly, said second rodcauses motions in inverse proportion to its own in said controllingmeans when the first rod remains motionless, the simultaneousdisplacement of said two rods ensuring the fuel supply for the aircraftengine as a function of the intake pressure,

of the barometric pressure, of the intake temperature and of therichness of the fuel mixture.

7. In a fuel flow regulator for supercharged aircraft engines, a fuelsupply, a first rod, a second rod, means for causing said first rod toslide as a function of the intake and barometric pressures, a thermostatlocated in the intake manifold of the engine, an airtight chamber, aconduit connecting said thermostat and chamber, a capsule filled with aliquid having a high coefficient of expansion in said chamber wherebydeformations of said capsule are proportional to the intake temperature,a lever for transmittin the motions of said capsule to said second rod,so that the slidings of said second rod are proportional to the intaketemperature, a shaft on which said lever is pivoted, a cam controllingthe position of said shaft, means for controlling the position of saidcam as a function of the position of the throttle, which is itself afunction of the richness of the fuel mixture, and of the flowcoeflicient to vary the proportion ratio of said lever and, consequentlythe amplitudes of the slidings of said second rod as a function of therichness of the fuel mixture, a second cam for the correction of thepossible lack of uniformity of the output from said fuel supply, saidrods being mounted to slide perp'endicularly to one another, a leverarm, means for causing the simultaneous displacement of said two rods toact on said lever arm, an auxiliary arm connected to said lever arm, aservomotor having a slide valve for controlling said fuel supply by thedisplacement of said auxiliary arm so that said first rod causes motionsproportional to its own of said slide valve, in case the second rodremains motionless, and similarly, said second rod causes motions ininverse proportion to its own of said slide valve when the first rodremains motionless, the simultaneous displacement of said two rods thusensuring the fuel supply for the aircraft engine as a function of theintake pressure, of the barometric pressure, of the intake temperatureand of the richness of the fuel mixture, a second lever for operatingsaid slide valve, a shaft on which said second lever is pivoted, meanscontrolled by said second cam for correcting the possible lack ofuniformity of the output of said fuel supply for displacing said lastnamed shaft parallel to said first rod and, consequently,perpendicularly to said second rod, to adjust the travel of said slidevalve and modify said fuel supply during very high or very low speeds.

DESIRE SCHMITT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,217,364 Halford et a1 Oct. 8,1940 2,245,562 Becker June 17, 1941 2,274,693 Heinrich et al Mar. 3,1942 2,383,563 Pugh et al. Aug. 28, 1945 2,388,669 Baker Nov. 13, 19452,403,398 Reggio July 2, 1946 2,416,797 Dodson Mar. 4, 1947 2,419,171Simpson et al Apr. 15, 1947 2,422,808 Stokes June 24, 1947 2,435,902Reggio Feb. 10, 1948 2,438,663 Greenland Mar. 30, 1948

